SCREENING YEAST FROM NATURAL HONEY, AND BEESWAX IN SON LA PROVINCE FOR LOW-ALCOHOL MEAD PRODUCTION

Son La is a northern mountainous province of Vietnam, where the climate and soil are suitable for various flowering plants and for many honey bee species to grow and produce high-quality honey. Yeasts in honey are expected to have valuable characteristics that can be applied in many fields. In this paper, seventy-two yeast strains isolated from natural honey and beeswax in Son La were screened for the ability of alcoholic fermentation to produce mead. Screening yeast strains for lowalcohol mead production were carried out based on the fermentation ability and the sensory of the final mead product. Yeast train NT95 was selected and characterized as Zygosaccharomyces sp. NT95. A suitable condition for the growth of Zygosaccharomyces sp. NT95 was Hansen broth containing a sugar concentration of 60 - 90 g\L at pH 4.0 - 4.5, and a temperature of 30 °C. A suitable condition for the alcoholic fermentation of Zygosaccharomyces sp. NT95 in the honey medium was at 30 °C with the inoculum of 5 x 107 cells\mL for 18 days. Under this condition, the mead produced by Zygosaccharomyces sp. NT95 contained approximately 4.5% alcohol (v\v) and the sensory score reached 14.51 ± 0.15 points. Further studies need to be done to improve the fermentation process and the completion of the product.